The invention relates to a screening device, which is intended for fibrous suspensions in the paper industry and is used for example with sorters, pressure screens and the like.
A screening device of the generic type, which has a substantially cylindrical screening device forming a screen surface, is known from EP 1 114 218 B1. The screening device is supported by a radially spaced-apart reinforcing device, which is designed in particular in the form of a support sleeve, also referred to as “backup cylinder”. The screening device is replaceable as a unit which allows easy replacement of the highly stressed screening device which is prone to wear and reuse of the reinforcing device, such as the support sleeve.
Screening plates and screening cylinders and methods for their production are known from EP 0 471 195 A1 and the corresponding U.S. Pat. No. 5,200,072. A cylindrical screening device is designed such that the screening device or the corresponding screening element is removably and replaceably connected to a support cylinder serving as a reinforcing device. To reduce the manufacturing cost and manufacturing time, a worn screening device thus only needs to be replaced, while the reinforcing device, in particular of the supporting cylinders can be reused. For the releasable connection between the screening device and the sleeve-like reinforcement device, the outer diameter of the screening device is sized slightly larger than the inner diameter of the support cylinder. The screening device and the reinforcing device are then frictionally connected to each other by a temperature-dependent shrink process, wherein this connection can optionally be secured, for example, by welding, with rivets, screws, adhesives, or solder.
Although a sometimes time-consuming and labor-consuming exchange of the screening device is contemplated in all these known screening devices, the screening device itself is a unitary structure which is as such releasably secured by suitable means inside the reinforcing device in the form of the support sleeve.